A supplement to The Herb Companion from the American Botanical Council and the Herb Research Foundation.
The beautiful blossom of the passionflower vine (Passiflora incarnata) is one of nature’s most intricate and delicate works. Also known as maypop or apricot vine, this fast-growing perennial herb has complex religious symbolism, a long history as a food source, and strong following as a medicinal plant.
The genus Passiflora, a member of the family Passifloraceae, explodes in diversity in the American Tropics with more than 400 species representing 95 percent of all passionflowers. The handful of temperate-climate species includes P. incarnata, which occurs from Virginia to southern Illinois and southeast Kansas and south to Florida and Texas.
What’s in a name?
The common and generic names, passionflower and Passiflora, refer to the Passion of Christ (his suffering following the Last Supper until his death). Early Spanish missionaries saw the structure of the flower as symbolizing elements of the Crucifixion: the three spreading styles with their knobby stigmas atop the ovary representing the three nails pinning Christ to the cross; the five stamens, the hammers used to drive the nails or Christ’s five wounds; the corona of colored filaments, a halo or perhaps the crown of thorns; and the five petals and five petallike sepals, ten apostles at the Crucifixion, all but Peter and Judas. The lobed leaves and tendrils were thought to represent, respectively, the hands and whips of Christ’s persecutors. The specific name incarnata is Latin for “flesh-colored”.
Food and medicine
In A Thousand Mile Walk to the Gulf, the naturalist John Muir (1838-1914) speaks of the passionflower vine as having a superb flower “and the most delicious fruit I have ever eaten”. Passionflower seeds found at prehistoric Native American sites in the eastern United States indicate that the fruits were enjoyed more than 5,000 years ago. Records attest that in the seventeenth century, the vines were at least being managed for fruit production by Algonquian peoples in Virginia.
Native Americans also drank passionflower tea to soothe nerves and poulticed crushed leaves on cuts and bruises. The earliest reference on American medicinal plants, Schoepf’s Materia Medica Americana published in Germany in 1787, mentioned the use of passionflower to treat epilepsy in the aged. About 1840, Dr. L. Phares of Mississippi introduced passionflower into medicine as a treatment for nervous anxiety, but the herb received little further attention until an Atlanta professor reintroduced it into the practice of Eclectic physicians some fifty years later.
During the next several decades, passionflower became widely known as an effective nervine and sedative. The dried flowering and fruiting tops were listed in National Formulary from 1916 to 1936 as a sedative and sleep aid, but in 1978, the Food and Drug Administration banned it from sleep aids after no evidence for its effectiveness was presented during hearings.
The fresh or dried whole plant, as well as teas, tinctures, fluid and solid extracts and chewing gums are accepted in Germany, France and other European countries as a treatment for nervous anxiety and sleep disturbances. Doses of 0.5 to 2.5 grams of the herb are taken three to four times a day. Passionflower is also combined with valerian and hawthorn to treat spasms and inflammation of the digestive tract.
Chemical components including flavonoids, small amounts of maltol and an essential oil, coumarin derivatives, and trace amounts of potentially toxic harman alkaloids have been identified from the leaves. Plant material used in European passionflower preparations contains at least 0.8 percent total flavonoids and less than 0.01 percent harman alkaloids. Standardized passionflower products contain from 0.8 to 2.6 percent flavonoids, generally considered to be the most active components of the plant, but no chemical compound or group of compounds has been identified as responsible for the herb’s sedative action.
Oral doses and abdominal cavity injections of water- or alcohol-based extracts of passionflower under various experimental conditions reduced brain stimulus and movement of laboratory rats. The injections also made them sleep significantly longer and protected them from chemically induced convulsions. However, these results could not be attributed to alkaloids or flavonoids in the extracts. A study testing passionflower both alone and in various combinations with other sedative herbs on laboratory animals found that at high doses, the combined herbs acted synergistically to increase sedation.
Other studies have shown that passionflower preparations reduce spasms, anxiety, and blood pressure, and that one constituent, passicol, inhibits the growth of fungi and other microorganisms.
Laboratory animals have experienced no toxicity or other adverse effects from passionflower extracts administered intravenously. The German monograph on passionflower lists no known contraindications, side effects, or drug interactions for human consumption.
Unfortunately, the only well-designed studies on the effects of passionflower on humans have been a handful involving passionflower in combination with other medicinal herbs. Further research on the herb alone is needed to establish how it works and how best to use it.
While passionflower is commonly regarded as a southern plant, it will grow as far north as Boston, and I suspect that with protection and a good mulch it would survive outdoors even in central Maine. Here in the Arkansas Ozarks, the native passionflower withstands temperatures of -25°F without any protection. (If you live near the northern edge of its range, passionflower seeds or plants originating in colder regions are likely to prove hardier than seeds or plants from the deep South. Check with your supplier before you buy.)
Although it dies back to the ground each year, passionflower makes a marvelous, fast-growing, climbing cover for a fence or trellis. In the South, it will grow 20 to 30 feet in a single season and is considered a weed in some places. In the North, expect a growth of about 15 feet in a season. Passionflower grows in waste places, thriving in relatively poor, sandy, acidic soils. Good drainage and full sun are essential.
Passionflower grows readily from seeds–if you are patient. To save seeds from fruits that you have harvested, remove them from the mucilaginous, fleshy aril surrounding them, then dry them in the shade. Store in a cold, dry location. Sow them the following spring 1/4 inch deep in light soil, preferably in flats or pots, where you can monitor the seeds more easily. They may germinate late in the summer or sit dormant until the following spring. Wait a year if you have to; your patience will be rewarded a few years hence when your vine bears fruit.
You can take 6-inch cuttings from mature plants and root them in sand indoors. Layering is easier but takes longer. Simply remove the leaves from a few inches of a stem in late summer and bury the denuded portion, leaving the leafy end of the stem sticking up. Water the area well. In a few weeks, the buried stem should begin to produce roots. Let the root system develop over the winter, then sever the stem between the buried part and the parent plant and transplant the new plant.
In late summer, when the fruits have ripened from yellowish to light brown (avoid overripe fruit: it tastes foul), open them and enjoy the delicious pulp. The slimy aril covering the seeds is also very sweet and fruity. You may run the pulp through a sieve or applesauce strainer to separate out the hard seeds.
ESCOP. Proposals for European Monographs on the Medicinal Uses of Passiflorae Herba. Vol. 2. Meppel, The Netherlands: European Scientific Cooperative for Phytotherapy, 1992.
Gremillion, K. J. “The Development of a Mutualistic Relationship between Humans and Maypops (Passiflora incarnata L.) in the Southeastern United States”. Journal of Ethnobiology 1989, 9(2):135-158.
Hoch, J. H. “The Legend and History of Passiflora”. American Journal of Pharmacy May 1934 [volume and number]:166-170.
Olin, B. R., ed. “Passion Flower”. The Lawrence Review of Natural Products. May 1989.
Speroni, E., and A. Minghetti. “Neuropharmacological Activity of Extracts from Passiflora incarnata”. Planta Medica 1988, 54:488-491.
“Herbs for Health” is offered bimonthly by the American Botanical Council and the Herb Research Foundation as a supplement to The Herb Companion.
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“Herbs for Health” is intended as an educational service, not a source of medical advice or a guide for self-medication. Please consult a qualified health-care professional for treatment of any serious health problems. For further information on any of the topics in “Herbs for Health”, write the American Botanical Council or the Herb Research Foundation.